PHOENIX -- Welcome to the Giants bullpen, Dan Otero.

Manager Bruce Bochy believes that any of his relievers can thrive in key situations. So Bochy allowed Otero to make his Major League debut in Saturday's fifth inning under somewhat critical circumstances. The Giants trailed, 4-2, and the Arizona Diamondbacks had their 3-4-5 hitters, Justin Upton, Miguel Montero and Chris Young, due up.

Otero yielded Montero's single and Young's RBI double, but recovered to escape a two-on, two-out jam before proceeding to throw a scoreless sixth inning. The Giants ultimately lost, 5-4.

"At first I was a little overly excited," said Otero, a 21st-round selection in the 2007 First-Year Player Draft who spent the previous five seasons toiling in the Giants' farm system. "I wish I had thrown two zeros. We'd still be playing right now."

Otero's fifth-inning lapse didn't bother Bochy.

"This spring, he showed great poise and a lot of confidence. That's why he made the club," Bochy said.

Mostly, Otero felt proud to break into the bigs.

"All in all, I felt I did a decent job," said Otero, whose parents and fiancee were in the Chase Field stands. "I gave up the game-winning run, so that's not exciting. But I'll remember this day forever."

Pill comes through with pinch-hit homer

PHOENIX -- You might say that Brett Pill gave it the old college try Saturday.

Pill said that he received plenty of pinch-hitting activity as a freshman at Cal State-Fullerton. Thus, despite spending his six professional seasons as a regular, he knows how to prepare himself to leave the bench and swing the bat.

"I keep busy in the [batting] cage," Pill said.

This trait served Pill and the Giants well, as he batted for Dan Otero in the seventh inning and lined Daniel Hudson's 0-1 pitch into the left-field seats for a two-run homer. That trimmed the Giants' deficit to 5-4, but the score froze there.

"[Hudson] threw a first-pitch slider and I kind of looked pretty dumb on it," Pill said. "So I figured he'd throw another one and I guessed right. He really hung that one."

Worth noting

• Continuity has not been characteristic of the Giants' Opening Day lineups in recent seasons. Pablo Sandoval has started at third base for four consecutive years, while catcher Buster Posey and first baseman Brandon Belt have two straight Opening Day starts apiece. Otherwise, the Giants have changed Opening Day starters at least three times at the five other non-pitching positions. The revolving door has spun most frequently in left field, where the Giants have introduced a new starter for six years in a row. Dating back from this year, this contingent features Aubrey Huff, Pat Burrell, Mark DeRosa, Fred Lewis, Dave Roberts and Barry Bonds.

• Javier Lopez and Jeremy Affeldt might struggle to top themselves this year in certain respects. According to STATS LLC, Lopez forced opposing hitters to swing and miss at his cutter 35.6 percent of the time, more than any other Major League reliever last season. That nearly doubled the league average of 18.7 percent for relievers inducing at least 150 swings. Affeldt ranked third among all relievers by coaxing contact-free swings with 47.3 percent of the curveballs he threw. The Major League average was 28.3. Affeldt and Lopez each have appeared once this season and are unscored upon.

• Buster Posey's hitting streak, which dated back to last season, ended Saturday at 14 games as he went 0-for-4.